{"id":515,"date":"2024-05-27T00:44:48","date_gmt":"2024-05-26T16:44:48","guid":{"rendered":"http:\/\/moyisuiying.com\/?p=515"},"modified":"2024-05-27T00:48:39","modified_gmt":"2024-05-26T16:48:39","slug":"%e6%b7%b1%e5%85%a5%e5%ad%a6%e4%b9%a0-mmap%e5%92%8cmunmap-%e5%8e%9f%e7%90%86","status":"publish","type":"post","link":"http:\/\/moyisuiying.com\/index.php\/os\/515.html","title":{"rendered":"\u6df1\u5165\u5b66\u4e60 mmap\u548cmunmap \u539f\u7406"},"content":{"rendered":"\n<h1>\u5e8f\u8a00<\/h1>\n\n\n\n<p>\u6700\u8fd1\u5728\u770b\u300aLinux\u9ad8\u6027\u80fd\u670d\u52a1\u5668\u7f16\u7a0b\u300b\u8fc7\u7a0b\u4e2d\uff0c\u5728\u9ad8\u7ea7I\/O\u51fd\u6570\u7ae0\u8282\u53d1\u73b0\u4e86mmap\u548cmunmap\u51fd\u6570\u7684\u539f\u7406\u548c\u7528\u6cd5\uff0c\u611f\u89c9\u5bf9\u4e8e\u4e2a\u4eba\u7406\u89e3\u96f6\u62f7\u8d1d\u4ee5\u53ca\u5171\u4eab\u5185\u5b58\u6709\u7740\u66f4\u6df1\u4e00\u6b65\u7684\u7406\u89e3\uff0c\u56e0\u6b64\u60f3\u8bb0\u5f55\u4e0b\u6765\uff0c\u4f9b\u5927\u5bb6\u4e00\u8d77\u5b66\u4e60\u5b66\u4e60\u3002<\/p>\n\n\n\n<h1>1. \u4f20\u7edf\u7684\u8bfb\u5199\u6587\u4ef6<\/h1>\n\n\n\n<p>\u4e00\u822c\u6765\u8bf4\uff0c\u4fee\u6539\u4e00\u4e2a\u6587\u4ef6\u7684\u5185\u5bb9\u9700\u8981\u5982\u4e0b3\u4e2a\u6b65\u9aa4\uff1a<\/p>\n\n\n\n<ul><li>\u628a\u6587\u4ef6\u5185\u5bb9\u8bfb\u5165\u5230\u5185\u5b58\u4e2d\u3002<\/li><li>\u4fee\u6539\u5185\u5b58\u4e2d\u7684\u5185\u5bb9\u3002<\/li><li>\u628a\u5185\u5b58\u7684\u6570\u636e\u5199\u5165\u5230\u6587\u4ef6\u4e2d\u3002<\/li><\/ul>\n\n\n\n<p>\u8fc7\u7a0b\u5982\u56fe 1 \u6240\u793a\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img  loading=\"lazy\" width=\"1024\" height=\"630\"  class=\"lazyload\" data-src=\"http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-1024x630.png\" src=\"https:\/\/cdn.jsdelivr.net\/gh\/moezx\/cdn@3.0.2\/img\/svg\/loader\/trans.ajax-spinner-preloader.svg\" onerror=\"imgError(this)\"  alt=\"\" class=\"wp-image-516\" srcset=\"http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-1024x630.png 1024w, http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-300x185.png 300w, http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-768x473.png 768w, http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image.png 1089w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure >\n<noscript><img loading=\"lazy\" width=\"1024\" height=\"630\" src=\"http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-1024x630.png\" alt=\"\" class=\"wp-image-516\" srcset=\"http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-1024x630.png 1024w, http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-300x185.png 300w, http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-768x473.png 768w, http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image.png 1089w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure><\/noscript>\n\n\n\n<p>\u5982\u679c\u4f7f\u7528\u4ee3\u7801\u6765\u5b9e\u73b0\u4e0a\u9762\u7684\u8fc7\u7a0b\uff0c\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>read(fd, buf, 1024); \u00a0\/\/ <code>\u8bfb\u53d6\u6587\u4ef6\u7684\u5185\u5bb9\u5230buf\n... \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \/\/ \u4fee\u6539buf\u7684\u5185\u5bb9<\/code>\nwrite(fd, buf, 1024); \/\/ \u628abuf\u7684\u5185\u5bb9\u5199\u5165\u5230\u6587\u4ef6<\/code><\/pre>\n\n\n\n<p>\u4ece\u56fe 1 \u4e2d\u53ef\u4ee5\u770b\u51fa\uff0c<code>\u9875\u7f13\u5b58(page cache)<\/code> \u662f\u8bfb\u5199\u6587\u4ef6\u65f6\u7684\u4e2d\u95f4\u5c42\uff0c\u5185\u6838\u4f7f\u7528 <code>\u9875\u7f13\u5b58<\/code> \u4e0e\u6587\u4ef6\u7684\u6570\u636e\u5757\u5173\u8054\u8d77\u6765\u3002\u6240\u4ee5\u5e94\u7528\u7a0b\u5e8f\u8bfb\u5199\u6587\u4ef6\u65f6\uff0c\u5b9e\u9645\u64cd\u4f5c\u7684\u662f <code>\u9875\u7f13\u5b58<\/code>\u3002<\/p>\n\n\n\n<h1>2. \u4f7f\u7528 mmap \u8bfb\u5199\u6587\u4ef6<\/h1>\n\n\n\n<p>\u4ece\u4f20\u7edf\u8bfb\u5199\u6587\u4ef6\u7684\u8fc7\u7a0b\u4e2d\uff0c\u6211\u4eec\u53ef\u4ee5\u53d1\u73b0\u6709\u4e2a\u5730\u65b9\u53ef\u4ee5\u4f18\u5316\uff1a\u5982\u679c\u53ef\u4ee5\u76f4\u63a5\u5728\u7528\u6237\u7a7a\u95f4\u8bfb\u5199 <code>\u9875\u7f13\u5b58<\/code>\uff0c\u90a3\u4e48\u5c31\u53ef\u4ee5\u514d\u53bb\u5c06 <code>\u9875\u7f13\u5b58<\/code> \u7684\u6570\u636e\u590d\u5236\u5230\u7528\u6237\u7a7a\u95f4\u7f13\u51b2\u533a\u7684\u8fc7\u7a0b\u3002<\/p>\n\n\n\n<p>\u90a3\u4e48\uff0c\u6709\u6ca1\u6709\u8fd9\u6837\u7684\u6280\u672f\u80fd\u5b9e\u73b0\u4e0a\u9762\u6240\u8bf4\u7684\u65b9\u5f0f\u5462\uff1f\u7b54\u6848\u662f\u80af\u5b9a\u7684\uff0c\u5c31\u662f <code>mmap<\/code>\u3002<\/p>\n\n\n\n<p>\u4f7f\u7528 <code>mmap<\/code> \u7cfb\u7edf\u8c03\u7528\u53ef\u4ee5\u5c06\u7528\u6237\u7a7a\u95f4\u7684\u865a\u62df\u5185\u5b58\u5730\u5740\u4e0e\u6587\u4ef6\u8fdb\u884c\u6620\u5c04\uff08\u7ed1\u5b9a\uff09\uff0c\u5bf9\u6620\u5c04\u540e\u7684\u865a\u62df\u5185\u5b58\u5730\u5740\u8fdb\u884c\u8bfb\u5199\u64cd\u4f5c\u5c31\u5982\u540c\u5bf9\u6587\u4ef6\u8fdb\u884c\u8bfb\u5199\u64cd\u4f5c\u4e00\u6837\u3002\u539f\u7406\u5982\u56fe 2 \u6240\u793a\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img  loading=\"lazy\" width=\"1024\" height=\"590\"  class=\"lazyload\" data-src=\"http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-1-1024x590.png\" src=\"https:\/\/cdn.jsdelivr.net\/gh\/moezx\/cdn@3.0.2\/img\/svg\/loader\/trans.ajax-spinner-preloader.svg\" onerror=\"imgError(this)\"  alt=\"\" class=\"wp-image-517\" srcset=\"http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-1-1024x590.png 1024w, http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-1-300x173.png 300w, http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-1-768x443.png 768w, http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-1.png 1308w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure >\n<noscript><img loading=\"lazy\" width=\"1024\" height=\"590\" src=\"http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-1-1024x590.png\" alt=\"\" class=\"wp-image-517\" srcset=\"http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-1-1024x590.png 1024w, http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-1-300x173.png 300w, http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-1-768x443.png 768w, http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-1.png 1308w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure><\/noscript>\n\n\n\n<p>\u524d\u9762\u6211\u4eec\u4ecb\u7ecd\u8fc7\uff0c\u8bfb\u5199\u6587\u4ef6\u90fd\u9700\u8981\u7ecf\u8fc7 <code>\u9875\u7f13\u5b58<\/code>\uff0c\u6240\u4ee5 <code>mmap<\/code> \u6620\u5c04\u7684\u6b63\u662f\u6587\u4ef6\u7684 <code>\u9875\u7f13\u5b58<\/code>\uff0c\u800c\u975e\u78c1\u76d8\u4e2d\u7684\u6587\u4ef6\u672c\u8eab\u3002\u7531\u4e8e <code>mmap<\/code> \u6620\u5c04\u7684\u662f\u6587\u4ef6\u7684 <code>\u9875\u7f13\u5b58<\/code>\uff0c\u6240\u4ee5\u5c31\u6d89\u53ca\u5230\u540c\u6b65\u7684\u95ee\u9898\uff0c\u5373 <code>\u9875\u7f13\u5b58<\/code> \u4f1a\u5728\u4ec0\u4e48\u65f6\u5019\u628a\u6570\u636e\u540c\u6b65\u5230\u78c1\u76d8\u3002<\/p>\n\n\n\n<p>Linux \u5185\u6838\u5e76\u4e0d\u4f1a\u4e3b\u52a8\u628a <code>mmap<\/code> \u6620\u5c04\u7684 <code>\u9875\u7f13\u5b58<\/code> \u540c\u6b65\u5230\u78c1\u76d8\uff0c\u800c\u662f\u9700\u8981\u7528\u6237\u4e3b\u52a8\u89e6\u53d1\u3002\u540c\u6b65 <code>mmap<\/code> \u6620\u5c04\u7684\u5185\u5b58\u5230\u78c1\u76d8\u6709 4 \u4e2a\u65f6\u673a\uff1a<\/p>\n\n\n\n<ul><li>\u8c03\u7528 <code>msync<\/code> \u51fd\u6570\u4e3b\u52a8\u8fdb\u884c\u6570\u636e\u540c\u6b65\uff08\u4e3b\u52a8\uff09\u3002<\/li><li>\u8c03\u7528 <code>munmap<\/code> \u51fd\u6570\u5bf9\u6587\u4ef6\u8fdb\u884c\u89e3\u9664\u6620\u5c04\u5173\u7cfb\u65f6\uff08\u4e3b\u52a8\uff09\u3002<\/li><li>\u8fdb\u7a0b\u9000\u51fa\u65f6\uff08\u88ab\u52a8\uff09\u3002<\/li><li>\u7cfb\u7edf\u5173\u673a\u65f6\uff08\u88ab\u52a8\uff09\u3002<\/li><\/ul>\n\n\n\n<h1>3.mmap\u7684\u4f7f\u7528\u65b9\u5f0f<\/h1>\n\n\n\n<h2>3.1 mmap\u51fd\u6570<\/h2>\n\n\n\n<pre class=\"wp-block-preformatted\">void *mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);<\/pre>\n\n\n\n<ul><li><code>start<\/code>\uff1a\u6307\u5b9a\u6620\u5c04\u7684\u865a\u62df\u5185\u5b58\u5730\u5740\uff0c\u53ef\u4ee5\u8bbe\u7f6e\u4e3a NULL\uff0c\u8ba9 Linux \u5185\u6838\u81ea\u52a8\u9009\u62e9\u5408\u9002\u7684\u865a\u62df\u5185\u5b58\u5730\u5740\u3002<\/li><li><code>length<\/code>\uff1a\u6620\u5c04\u7684\u957f\u5ea6\u3002<\/li><li><code>prot<\/code>\uff1a\u6620\u5c04\u5185\u5b58\u7684\u4fdd\u62a4\u6a21\u5f0f\uff0c\u53ef\u9009\u503c\u5982\u4e0b\uff1a<ul><li><code>PROT_EXEC<\/code>\uff1a\u53ef\u4ee5\u88ab\u6267\u884c\u3002<\/li><\/ul><ol><li><code>PROT_READ<\/code>\uff1a\u53ef\u4ee5\u88ab\u8bfb\u53d6\u3002<\/li><li><code>PROT_WRITE<\/code>\uff1a\u53ef\u4ee5\u88ab\u5199\u5165\u3002<\/li><li><code>PROT_NONE<\/code>\uff1a\u4e0d\u53ef\u8bbf\u95ee\u3002<\/li><\/ol><\/li><li><code>flags<\/code>\uff1a\u6307\u5b9a\u6620\u5c04\u7684\u7c7b\u578b\uff0c\u5e38\u7528\u7684\u53ef\u9009\u503c\u5982\u4e0b\uff1a<ul><li><code>MAP_FIXED<\/code>\uff1a\u4f7f\u7528\u6307\u5b9a\u7684\u8d77\u59cb\u865a\u62df\u5185\u5b58\u5730\u5740\u8fdb\u884c\u6620\u5c04\u3002<\/li><\/ul><ol><li><code>MAP_SHARED<\/code>\uff1a\u4e0e\u5176\u5b83\u6240\u6709\u6620\u5c04\u5230\u8fd9\u4e2a\u6587\u4ef6\u7684\u8fdb\u7a0b\u5171\u4eab\u6620\u5c04\u7a7a\u95f4\uff08\u53ef\u5b9e\u73b0\u5171\u4eab\u5185\u5b58\uff09\u3002<\/li><li><code>MAP_PRIVATE<\/code>\uff1a\u5efa\u7acb\u4e00\u4e2a\u5199\u65f6\u590d\u5236\uff08Copy on Write\uff09\u7684\u79c1\u6709\u6620\u5c04\u7a7a\u95f4\u3002<\/li><li><code>MAP_LOCKED<\/code>\uff1a\u9501\u5b9a\u6620\u5c04\u533a\u7684\u9875\u9762\uff0c\u4ece\u800c\u9632\u6b62\u9875\u9762\u88ab\u4ea4\u6362\u51fa\u5185\u5b58\u3002<\/li><\/ol><\/li><li><code>fd<\/code>\uff1a\u8fdb\u884c\u6620\u5c04\u7684\u6587\u4ef6\u53e5\u67c4\u3002<\/li><li><code>offset<\/code>\uff1a\u6587\u4ef6\u504f\u79fb\u91cf\uff08\u4ece\u6587\u4ef6\u7684\u4f55\u5904\u5f00\u59cb\u6620\u5c04\uff09\u3002<\/li><\/ul>\n\n\n\n<h2>3.2 mmap\u7684\u4f7f\u7528<\/h2>\n\n\n\n<pre class=\"wp-block-preformatted\">int fd = open(filepath, O_RDWR, 0644); &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; \/\/ \u6253\u5f00\u6587\u4ef6<br>void *start = mmap(NULL, 8192, PROT_WRITE, MAP_SHARED, fd, 4096); \/\/ \u5bf9\u6587\u4ef6\u8fdb\u884c\u6620\u5c04<\/pre>\n\n\n\n<p>\u5728\u4e0a\u9762\u4f8b\u5b50\u4e2d\uff0c\u6211\u4eec\u5148\u901a\u8fc7 <code>open<\/code> \u51fd\u6570\u4ee5\u53ef\u8bfb\u5199\u7684\u65b9\u5f0f\u6253\u5f00\u6587\u4ef6\uff0c\u7136\u540e\u901a\u8fc7 <code>mmap<\/code> \u51fd\u6570\u5bf9\u6587\u4ef6\u8fdb\u884c\u6620\u5c04\uff0c\u6620\u5c04\u7684\u65b9\u5f0f\u5982\u4e0b\uff1a<\/p>\n\n\n\n<ul><li><code>start<\/code> \u53c2\u6570\u8bbe\u7f6e\u4e3a NULL\uff0c\u8868\u793a\u8ba9\u64cd\u4f5c\u7cfb\u7edf\u81ea\u52a8\u9009\u62e9\u5408\u9002\u7684\u865a\u62df\u5185\u5b58\u5730\u5740\u8fdb\u884c\u6620\u5c04\u3002<\/li><li><code>length<\/code> \u53c2\u6570\u8bbe\u7f6e\u4e3a 8192 \u8868\u793a\u6620\u5c04\u7684\u533a\u57df\u4e3a 2 \u4e2a\u5185\u5b58\u9875\u7684\u5927\u5c0f\uff08\u4e00\u4e2a\u5185\u5b58\u9875\u7684\u5927\u5c0f\u4e3a 4 KB\uff09\u3002<\/li><li><code>prot<\/code> \u53c2\u6570\u8bbe\u7f6e\u4e3a <code>PROT_WRITE<\/code> \u8868\u793a\u6620\u5c04\u7684\u5185\u5b58\u533a\u4e3a\u53ef\u8bfb\u5199\u3002<\/li><li><code>flags<\/code> \u53c2\u6570\u8bbe\u7f6e\u4e3a <code>MAP_SHARED<\/code> \u8868\u793a\u5171\u4eab\u6620\u5c04\u533a\u3002<\/li><li><code>fd<\/code> \u53c2\u6570\u8bbe\u7f6e\u6253\u5f00\u7684\u6587\u4ef6\u53e5\u67c4\u3002<\/li><li><code>offset<\/code> \u53c2\u6570\u8bbe\u7f6e\u4e3a 4096 \u8868\u793a\u4ece\u6587\u4ef6\u7684 4096 \u5904\u5f00\u59cb\u6620\u5c04\u3002<\/li><\/ul>\n\n\n\n<p><code>mmap<\/code> \u51fd\u6570\u4f1a\u8fd4\u56de\u6620\u5c04\u540e\u7684\u5185\u5b58\u5730\u5740\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u6b64\u5185\u5b58\u5730\u5740\u5bf9\u6587\u4ef6\u8fdb\u884c\u8bfb\u5199\u64cd\u4f5c\u3002\u6211\u4eec\u901a\u8fc7\u56fe 3 \u5c55\u793a\u4e0a\u9762\u4f8b\u5b50\u5728\u5185\u6838\u4e2d\u7684\u7ed3\u6784\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img  loading=\"lazy\" width=\"1024\" height=\"549\"  class=\"lazyload\" data-src=\"http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-2-1024x549.png\" src=\"https:\/\/cdn.jsdelivr.net\/gh\/moezx\/cdn@3.0.2\/img\/svg\/loader\/trans.ajax-spinner-preloader.svg\" onerror=\"imgError(this)\"  alt=\"\" class=\"wp-image-518\" srcset=\"http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-2-1024x549.png 1024w, http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-2-300x161.png 300w, http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-2-768x412.png 768w, http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-2.png 1461w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure >\n<noscript><img loading=\"lazy\" width=\"1024\" height=\"549\" src=\"http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-2-1024x549.png\" alt=\"\" class=\"wp-image-518\" srcset=\"http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-2-1024x549.png 1024w, http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-2-300x161.png 300w, http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-2-768x412.png 768w, http:\/\/moyisuiying.com\/wp-content\/uploads\/2024\/05\/image-2.png 1461w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure><\/noscript>\n\n\n\n<h1>4.munmap\u7684\u4f7f\u7528\u65b9\u5f0f<\/h1>\n\n\n\n<h2>4.1 munmap\u51fd\u6570<\/h2>\n\n\n\n<h2>4.2munmap\u7684\u4f7f\u7528<\/h2>\n\n\n\n<pre class=\"wp-block-preformatted\">int munmap(void *start,size tlength );<\/pre>\n\n\n\n<ul><li><code>start<\/code>\uff1a\u6307\u5b9a\u6620\u5c04\u7684\u865a\u62df\u5185\u5b58\u5730\u5740\uff0c\u7531mmap()\u65b9\u6cd5\u8fd4\u56de\u7684\u8d77\u59cb\u865a\u62df\u5185\u5b58\u5730\u5740\u3002<\/li><li><code>length<\/code>\uff1a\u6620\u5c04\u7684\u957f\u5ea6\u3002<\/li><\/ul>\n\n\n\n<h2>4.2 mmap\u7684\u4f7f\u7528<\/h2>\n\n\n\n<pre class=\"wp-block-preformatted\">int fd = open(filepath, O_RDWR, 0644); &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; \/\/ \u6253\u5f00\u6587\u4ef6<br>void *start = mmap(NULL, 8192, PROT_WRITE, MAP_SHARED, fd, 4096); \/\/ \u5bf9\u6587\u4ef6\u8fdb\u884c\u6620\u5c04<br>int errNo = munmap(start,8192 ); \/\/ \u89e3\u9664\u6620\u5c04\uff0c\u5e76\u8fd4\u56de\u9519\u8bef\u7801<\/pre>\n\n\n\n<p>\u5728\u4e0a\u9762\u4f8b\u5b50\u4e2d\uff0c\u6211\u4eec\u5148\u901a\u8fc7 <code>open<\/code> \u51fd\u6570\u4ee5\u53ef\u8bfb\u5199\u7684\u65b9\u5f0f\u6253\u5f00\u6587\u4ef6\uff0c\u7136\u540e\u901a\u8fc7 <code>mmap<\/code> \u51fd\u6570\u5bf9\u6587\u4ef6\u8fdb\u884c\u6620\u5c04\uff0c\u6620\u5c04\u7684\u65b9\u5f0f\u5982\u4e0b\uff1a<\/p>\n\n\n\n<h1>5.\u603b\u7ed3<\/h1>\n\n\n\n<p>\u4ece\u5bf9mmap\u548cmunmap\u51fd\u6570\u7684\u7406\u89e3\u770b\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u65b9\u6cd5\u53c2\u6570\u4ee5\u53ca\u8fd4\u56de\u7684\u7ed3\u679c\u53bb\u52a0\u6df1\u5bf9\u865a\u62df\u5185\u5b58\u6620\u5c04\u7684\u7406\u89e3\uff0c\u8fd9\u5bf9\u4e8e\u6211\u4eec\u4e4b\u540e\u5b66\u4e60\u96f6\u62f7\u8d1d\u548c\u5171\u4eab\u5185\u5b58\u5176\u5b9e\u662f\u6709\u52a9\u76ca\u7684\u3002<\/p>\n\n\n\n<h1>6.\u53c2\u8003\u6587\u6863<\/h1>\n\n\n\n<ol><li><a href=\"https:\/\/juejin.cn\/post\/6961303425715798023?searchId=202405270031451D4519D65847FA0C20B2\" target=\"_blank\"  rel=\"nofollow\" >https:\/\/juejin.cn\/post\/6961303425715798023?searchId=202405270031451D4519D65847FA0C20B2<\/a><\/li><\/ol>\n","protected":false},"excerpt":{"rendered":"<p>\u5e8f\u8a00 \u6700\u8fd1\u5728\u770b\u300aLinux\u9ad8\u6027\u80fd\u670d\u52a1\u5668\u7f16\u7a0b\u300b\u8fc7\u7a0b\u4e2d\uff0c\u5728\u9ad8\u7ea7I\/O\u51fd\u6570\u7ae0\u8282\u53d1\u73b0\u4e86mmap\u548cmunmap\u51fd\u6570\u7684\u539f\u7406\u548c\u7528\u6cd5\uff0c\u611f\u89c9\u5bf9\u4e8e\u4e2a\u4eba &#8230;<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[72],"tags":[232],"_links":{"self":[{"href":"http:\/\/moyisuiying.com\/index.php\/wp-json\/wp\/v2\/posts\/515"}],"collection":[{"href":"http:\/\/moyisuiying.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/moyisuiying.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/moyisuiying.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/moyisuiying.com\/index.php\/wp-json\/wp\/v2\/comments?post=515"}],"version-history":[{"count":2,"href":"http:\/\/moyisuiying.com\/index.php\/wp-json\/wp\/v2\/posts\/515\/revisions"}],"predecessor-version":[{"id":521,"href":"http:\/\/moyisuiying.com\/index.php\/wp-json\/wp\/v2\/posts\/515\/revisions\/521"}],"wp:attachment":[{"href":"http:\/\/moyisuiying.com\/index.php\/wp-json\/wp\/v2\/media?parent=515"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/moyisuiying.com\/index.php\/wp-json\/wp\/v2\/categories?post=515"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/moyisuiying.com\/index.php\/wp-json\/wp\/v2\/tags?post=515"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}